Electric incandescent lamp



Jan. 26, 1954 H. E. HERMANSON ET AL 2,667,594

ELECTRIC INCANDESCENT LAMP Filed Jan. 2, 1951 Invervtors Hevman E.Hermansoh, Fredrick S.Lamb, y K-7-- Theh- A htornea.

Patented Jan. 26, 1954 2,667,594 ELECTRIC IN CANDESCENT LAMP Herman E.Hermanson,

Fredrick S.

Lamb, Cle

assignors to General El poration of New York Application January 2,1951,

East Cleveland, and

veland Heights, Ohio, ectric Company, a. cor- Serial N 0. 203,837

6 Claims. (Cl. 313274) Our invention relates to electric incandescentlamps and similar devices, and more particularly to a mount structuretherefor. The invention is of particular utility in connection withelectric incandescent lamps of the double-ended tubular type having abase at each end and a filament extending longitudinally of the lamp,such as shown and described in U. S. Patent 2,032,791, Cartun, and2,158,949, Blake, assigned to the assignee of the present invention.

Lamps of the above-mentioned double-ended tubular type are in generaluse at present and comprise a tubular glass envelope having metal endcaps or bases sealed to the opposite ends thereof and an elongated mountsupported within the envelope between the metal end caps. The mountcomprises an elongated filament extending longitudinally of the envelopeand supported at a plurality of spaced points along its length by anumber of anchor wires insulatively fastened, by means of glass beads,to an elongated stay member which is resiliently compressiblelongitudinally between and supported in place by the end caps of theenvelope. The stay mem ber comprises a main or center section preferablyformed of a metal channel so as to possess adequate rigidity andprovided at itsopposite ends with terminal wires or end conductors whichare electrically connected to the ends of the filament and which bearagainst the end caps to make electrical connection therewith.

Heretofore, the glass support beads for the filament anchor wires ofsuch lamp mounts have been attached or fastened in place on the metalchannel by means of a fused seal therebetween, the glass beads beingsecurely held in place by the bond between the glass and the metal ofwhich the channel is formed. Such a fused seal type of attachment of theglass beads to the metal channel requires the use of a suitable metalfor the channel which will readily wet and adhere to the glass of whichthe support beads are made. Up to the present the metal most suitableand preferably employed for this purpose has been a special high-chromeiron alloy of the so-called stainlesssteel type. Such a material,however, is quite expensive, thus adding materially to the cost of thefinished lamp.

It is an object of our invention, therefore, to provide an electricincandescent lamp of the above-mentioned general type having a mountstructure of simple and relatively inexpensive construction and easy tofabricate.

Another object of our invention is to provide an electricincandescentlamp of the above-mentioned general type having a lamp mountin which the glass beads which support the filament anchor wires arefastened to the stay member of the mount by means of a mechanicalinterlock therebetween.

According to the invention, the opposite side walls of thechannel-shaped stay member of the lamp mount are deformed laterally ofthe channel at corresponding opposite points spaced therealong, as byinward or outward indentations therein, to form locking shouldersthereon which are at least partially embedded in the glass support beadsfor the anchor wires to thereby key and mechanically lock the glassbeads in place on the channel.

Further objects and advantages of our invention will appear from thefollowing description of a species thereof and from the accompanyingdrawing.

In the drawing, Fig. l is a longitudinal sectional view, partly inelevation, of an electric incandescent lamp according to the invention;Fig. 2 is an enlarged fragmentary perspective view of the mountstructure of the lamp shown in Fig. 1; Fig. 3 is an enlarged transversesection of the mount structure taken on the line 33 of Fig. 2; and Fig.4 is a sectional view ilthe method of forming the glass beads andattaching them to the channel member of the mount structure.

Referring to the drawing, the lamp there shown is of the double-endedtubular type shown in the above-mentioned U. S. Patents 2,032 791 anaperture 7 at the center of the end cap 3, the said aperture beingsealed by a mass of glass tipped-01f residue of a 8 which constitutesthe glass exhaust tube and.

ll, channel member ['3 at a slight angle relative free or outer'ends arebent to extend transversely of extent longitudinally thereof.

small glass support beads 3 which is sheltered within the cavity formedby the boss 5.

Mounted within and extending longitudinally of the envelope I is anelongated lamp mount 9 according to the invention comprising a filamentsupport structure Ill and an elongated filament ll supported thereby.The filament support structure H! comprises a stay member 1200mposed ofan elongated straight center section 13 extending longitudinally thewall thereof and provided at its opposite ends with terminal wire orconductor extensions l4, l5. The center section 13 of stay member I2 ispreferably in the form of an approximately V- shaped channel member toone end of whichthe terminal wire 44 is electrically connected as bywelding. The other terminal wire i5 is insulatively secured to the otherend of the channel member l3 by a short length of glass rod IS in whichthe respective ends of the channel member l3 and wire it are embedded.

As shown, the terminal wires or end conductors l5 extend from theopposite ends of the thereto, and their the channel member 13 and-areformed into loops ll which encircle the bosses 5, 6 on the respectivelyadjacentend caps to thereby position the lamp mount 9 within theenvelope i with the filament ll extending more or less axially of thesaid envelope. The loop IT on one or both terminal wires Ill, i5 isinitially formed with a slight pitch or spiral shape, i. e., it isformed as a coil of less than one full turn, for the purpose of makingthe stay member l2 resiliently compress ble to a slight During themanufacture of the lamp, the spiral-shaped loop or loops 11 more or lessflatten out as the stay mom-- *ber I2 is compressed between the oppositeend the loops il thus resiliently bearing against the concave inner sideof the end caps and'so making good electrical contact therewith.

The filament H is in the form of a coiled caps 3, 4,

tungsten wire which extends substantiallythc entire'length and axiallyof the is stretched out and clamped envelope i and or otherwiseelectrically connected at its ends to short spur wires 48, i9 welded tothe terminal wires id, id, re-

filament ii is additionally supspectively. The ported at intermediatepoints along its length by one or more support or anchor wires 23extending from the channel member it at spaced points therealong, thesaid support wires being provided at one end with filament supportingloops 2| and being secured at their other ends and insulated from thechannel member by means of 22 in which thesupport wires 20 are embedded.

In accordance with the invention, the glass beads 22, in place of beingfastened to and held in place on the channel member 53 by means of afused glass-to-metal seal as has heretofore been the practice, aremechanically anchored to the channel member instead. For such purpose,the channel member 13 is formed, at spaced points along its lengthcorresponding to the location of the glass beads thereon, with lockingshoulders provided, in this instance, by small lateral deformations orboth of the side walls 2d of the channel member l3, preferably at theirupper or free edges 25, as shown. The said indentations 23 arepreferably provided in both of the side walls 24 of the channel atcorresponding opposite points of the tube 2 adjacent or indentations Sin one and be locked in place bead to the channel member.

spaced along its length. The glass beads 22 engage and are immovablyheld in place on the channel member I 3 by the said locking shoulders,the glass beads substantially filling the interior cross-sectional spaceof the channel at the respective indentations 23 (Fig. 3) so as toengage on the channel member 13 by the indentations. As shown in Fig. 3,the glass of the beads 22 preferably extends over the free longitudinaledges 25 of the channel member l3 and down around the outer sidesthereof, as indicated at 26, so as to actually embed the indentededgeportions 23 of the channel member. The result, therefore, is a secureand strong clamping mechanical interlock of the glass beadto-t-hechannel such as effectively holds the bead immovably in place onthe channel.

As shown in Fig. 4, the glass beads 22 are each formed from a shortlength of relatively small diameter glass rod or a pressed powderedglass pellet 27. The glass rod 2? is suitably heated at one end to aplastic condition and the said heated end then pressed down into thechannel member it (which is also preferably heated to a slight degree)at the region of the respective group of indentations therein so as tocause the softened glass to substantially fill the interiorcross-sectional space of the channel at said point (Fig. 3) and alsoflow down over the outside surfaces of the side walls 24 of the channelmember, as shown at 26 in Fig. 3, thus embedding the indented edgeportions 23 of the channel member in the glass and thereby securelylocking the glass After the attachment of the glass rods 21 to thechannel member i3, the upper ends of the rods 21 are heated to a plasticcondition and fused down, whereupon the support wires 20 are insertedendwise into and embedded in the glass to complete the support wiremounting.

Inasmuch as the attachment of the glass beads fected by automatic meanssuch as causes the location of the glass beads lengthwise of the channelmember l3' to vary within small limits, it is preferable that a seriesor group (e. g., two or three) of contiguous identations 23 be providedin the channel member i3 at the approximate location of each bead 22 soas to allow for any such slight variation in bead location and assurethat the glassbead'will engage or embed at least a part of one or moreof the indentations 23 of its respective group and become locked to thechannel. The mechanical fastening of the glass beads 22 to the channelmember l3 in accordance with the invention therefore permits the use ofan ordinary and much less expensive metal for the channel member thanthe high chrome-iron alloy heretofore employed for such purpose. Thusthe channel member l3 may be formed of ordinary rolled iron or steel,for instance, as a result of which the cost of the lamp mount 9 and ofthe finished lamp is considerably reduced.

Although a preferred embodiment of our invention has been disclosed, itwill be apparent that the invention is not tobe limited to the specificconstruction and arrangement of parts shown but that they may be widelymodified within the spirit and scope of our invention as defined by theappended claims.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

1.- An electric lamp comprising a glassenvelope. a mount within saidenvelope comprisingan elongated filament and an elongated metallic staymember extending longitudinally of the filament and carrying supportwires engaging and supporting the filament at spaced points therealong,said stay member comprising a metal channel provided at spaced pointstherealong with lateral deformations in at least one of its side Walls,and glass beads insulatively fastening said support wires to saidchannel, said channel being of a metal incapable of readily forming anadherent bond with the glass of said beads, and said glass beads beingshaped in situ in engaging and interlocking relation with the saiddeformations to mechanically hold the beads immovably in place on saidchannel against movement longitudinally as well as laterally thereof.

2. An electric lamp comprising a glass envelope, a mount within saidenvelope comprising an elongated filament and an elongated metallic staymember extending longitudinally of the filament and carrying supportwires engaging and supporting the filament at spaced points therealong,said stay member comprising a metal channel provided with longitudinallyspaced indentations in at least one of its side walls, and glass beadsinsulatively fastening said support wires to said channel, said channelbeing of a metal incapable of readily forming an adherent bond with theglass of said beads, and said glass beads substantially filling theinterior cross-sectional space of said channel at the region ofrespective ones of said indentations and being shaped in situ inengaging and interlocking relation with the said indentations tomechanically hold the beads immovably in place on said channel againstmovement longitudinally as well as laterally thereof.

3. An electric lamp comprising a glass envelope, a mount within saidenvelope comprising an elongated filament and an elongated metallic staymember extending longitudinally of the filament and carrying supportwires engaging and supporting the filament at spaced points therealong,said stay member comprising a metal channel having the free edge portionof at least one of its side walls inwardly indented at spaced pointstherealong to provide locking indentations, and glass beads insulativelyfastening said support wires to said channel, said channel being of ametal incapable of readily forming an adherent bond with the glass ofsaid beads, and said glass beads substantially filling the interiorcross-sectional space of said channel at the region of respective onesof said indentations and being shaped in situ into at least partiallyembedding relation with the indented free edge portions of said channelto mechanically lock the beads to the channel and hold them immovably inplace thereon against movement longitudinally as well as laterallythereof.

4. An electric lamp comprising a glass envelope, a mount Within saidenvelope comprising an elongated filament and an elongated metallic staymember extending longitudinally of the filament and carrying supportwires en aging and supporting the filament at spaced points therealong,said stay member comprising a metal channel having the free edgeportions of both its side walls indented to provide opposed sets ofindentations spaced apart longitudinally of the channel, and glass beadsinsulatively fastening said support wires to said channel, said channelbeing of a metal incapable of readily forming an adherent bond with theglass of said beads, and said glass beads substantially filling theinterior cross-sectional space of said channel at the region ofrespective sets of said indentations and being shaped in situ into atleast partially embedding relation with the latter to mechanically lockthe beads to the channel and hold them immovably in place thereonagainst movement longitudinally as Well as laterally thereof.

5. An electric lamp comprising a glass envelope, a mount Within saidenvelope comprising an elongated filament and an elongated metallic staymember extending longitudinally of the filament and carrying supportwires engaging and supporting the filament at spaced points therealong,said stay member comprising a metal channel having the free edgeportions of both its side walls indented to provide longitudinallyspaced groups of contiguous opposed sets of indentations, and glassbeads insulatively fastening said support wires to said channel, saidchannel being of a metal incapable of readily forming an adherent shapedin situ into at least partially embedding relation with the indentationsof at least one of the said opposed sets thereof in its respective groupto mechanically lock the beads to the channel and hold them immovably inplace thereon against movement longitudinally as well as laterallythereof.

6. A lamp mount comprising an elongated stay member, an elongatedfilament extending longitudinally of said stay member and supportedtherefrom, a plurality of support wires carried by said stay member andengaging and supporting the filament at spaced points therealong, saidstay member comprising a metal channel having the free edge portion ofat least one of its side walls inwardly indented at spaced pointstherealong to provide locking indentations, and glass beads insulativelyfastening said support wires to said channel, said channel being of aHERMAN E. HERMANSON.

FREDRICK S. LAM References Cited in the file of this patent UNITEDSTATES PATENTS Number Name Date 1,306,912 Keyes June 17, 1919 1,607,515Duncan Nov. 16, 1926 1,649,907 Mayer Nov. 22, 1927 1,662.032 MullaneyMar. 6, 1928 1,884,957 Adams Oct. 25, 1932 2,082,616 Cartun June 1, 19372,425,865 Cartun Aug. 19, 1947 2,434,779 Willis Jan. 20, 1948

